Maximum rpm for SB

My 69 Swinger has a 340 that will Zing 9000,I do know it is a 340 with a pair of X heads and is a solid lift engine but other than that I know absolutely nothing,I have never even had a valve cover off of it. I am looking forward to tearing it apart one day to see just exactly what is inside. I do Think that the swinger will outrun my 67 chevelle SS and the SS has a built big block with about 450 HP or maybe even 500. Wish I would have had it dynoed when it was built and before it was put in the chevelle to be certain of the HP but with all it has and what was done it should be pushing around 500 HP.

Bobby Dodson